Science: Section 4
Air Pollution and Health
Air pollution is harmful to us all, as it can affect our bodies, the food we eat, the places we live and the world we live in.
Our bodies need oxygen to survive. We breathe in thousands of litres of oxygen a day but the air we breathe is not pure. It can contain various substances called pollutants and many of these arise from burning fuels. This pollution can affect our health.
There are many sources of both manmade and natural air pollution. Natural air pollution can come from volcanoes, desert dust and wildfires. Manmade air pollution can come from transport, industry and energy generation.
In urban areas, such as towns and cities, cars, buses and trucks are the main contributor to poor air quality.
Pollutants
Click the X at the top right of this window to close this window then click the pink spots on the graphic to learn more about that pollutant.
Power
Stop and think for a moment how much gas or electricity you have used since you got up this morning. Did you know that the power we use in our homes, communities and workplaces is generated by burning other fuels? These fuels include coal, gas and oil. When these fuels are burned to generate power they release pollutants, such as sulphur dioxide and other greenhouse gases into our atmosphere.
Agriculture
We have lots of farms that rear cows and sheep for either their meat, milk or for their wool or hide but one thing they produce that we don’t necessarily want is the gas methane. Methane is produced by livestock after they eat and digest grass and this is broken up by bacteria to produce methane which then makes its way into the air when the animal releases wind. Methane is one of the main greenhouse gases which can cause climate change and livestock is the biggest source of methane. As well as this, particulates (PM10) can arise through dust being blown off farmer’s fields.
Weather
Although many contributing factors can be found in any one place it is important to note that the weather can affect air pollution levels. The wind for example can carry and move pollutants from one area to another and spread them out. On a windy day air pollution levels might be lower than you would expect. Likewise a very calm day may see higher than expected levels as there is no wind to take away the pollutants. The rain can also affect air pollution by washing out pollutants from the air.
Transport
Think of a road close to your school or home. How many vehicles do you think travel along that road each day? Each car, van, bus, lorry and motorbike that travels along that road produces pollutants such as carbon monoxide, particulate matter and nitrogen oxide, which are generated by the burning of diesel or petrol that powers each vehicle. A busy road with a lot of vehicles would see higher levels of air pollution. If you think of all the roads within your town or city, or even within Scotland, it is easy to see how road transport is one of the most significant contributing factors to air pollution.
Towns & Cities
Towns and cities suffer from the highest levels of air pollution. If you think about what you have already learned about waste, power and transport it is no surprise then that air pollution can be so high. Think about the sheer number of cars, buses, factories and homes, all found in one town or city and the volume of pollutants that each one creates.
Natural Sources
Natural sources of pollutants from naturally occurring process or events can also put pollutants into the air. An active volcano can produce smoke, ash, carbon dioxide and sulphur dioxide that all goes up into the air. Forest fires sparked by very hot and dry weather conditions can emit carbon monoxide, sulphur dioxide, nitrogen dioxide, ozone, and particulate matter into the air. All of which contribute to air pollution.
Waste
Every day we throw out bags and bags of rubbish. Some might get recycled, some might be burned to produce energy with the rest sent to landfill where it rots and decomposes in the ground. As it rots it produces methane which as we have already learned is a major greenhouse gas.
Power
Stop and think for a moment how much gas or electricity you have used since you got up this morning. Did you know that the power we use in our homes, communities and workplaces is generated by burning other fuels? These fuels include coal, gas and oil. When these fuels are burned to generate power they release pollutants, such as sulphur dioxide and other greenhouse gases into our atmosphere.
Impacts of air pollution on human health
The quality of the air around us is very important as it directly affects our health and the environment we live in. Air pollution is estimated to reduce the average life expectancy of every person in the UK by six months and causes around 2000 deaths in Scotland each year.
Air pollution has become one of the biggest environmental risks to human health. Unlike the dense smog and smoking chimneys of the past, today’s air pollution is largely considered invisible. Health problems are mainly caused by fine particles from car exhausts that can be breathed deep into the lungs.
For the majority of people, the health effects of air pollution are relatively minor and go unnoticed; however, sometimes we can experience very mild symptoms following short periods of exposure. This can include irritation to the nose and throat after walking down a heavily congested city centre street.
For those people who have pre-existing health problems such as asthma, or who are exposed on a long-term basis, or to high levels of air pollutants, the effects increase in severity. This can include the worsening of existing medical conditions and increased visits to the doctor, to admission to hospital and, in extreme cases, premature death.
The diagram below shows the impact that air pollution can have on different parts of our body.
There is also a Homework Sheet you can download that supports and develops further the ideas from this section.
